That picture is mis-labeled. The top knife is the ES1-M all right, but the bottom one is one of the protypes Ernie made for the guys at Bragg to try out. They liked the knife, but inexplicably wanted thumb discs instead of holes. If any exist other than the one Ernie kept, there were probably five made totally.
The ES1-C was to be the same as the thumb disc knife pictured, only without the wave. He originally intended to provide only the SEALS with the wave, and in fact took orders on the knife stipulating that only the civvie version would be available to the general public. Fortunately for everyone, he changed his mind on that, allowing civilians to get the same ES1-Ms as the Navy (often from the same batches). And then along came the Commander and the rest is history....